import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class Test1 {
    public static void main(String[] args) {
                Data2 data = new Data2();
                new Thread(()->{
                    for (int i = 0; i < 10; i++) {
                        try {
                            data.increment();
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                },"A").start();
                new Thread(()->{
                    for (int i = 0; i < 10; i++) {
                        try {
                            data.decrement();
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                },"B").start();
                new Thread(()->{
                    for (int i = 0; i < 10; i++) {
                        try {
                            data.increment();
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                },"C").start();
                new Thread(()->{
                    for (int i = 0; i < 10; i++) {
                        try {
                            data.decrement();
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                    }
                },"D").start();
            }
        }
class Data2{ // 数字 资源类
    private int number = 0;
    Lock lock = new ReentrantLock();
    Condition condition = lock.newCondition();
    //condition.await(); // 等待
    //condition.signalAll(); // 唤醒全部
    //+1
    public void increment() throws InterruptedException {
        lock.lock();
        try {
            // 业务代码
            while (number!=0){ //0
                // 等待
                condition.await();
            }
            number++;
            System.out.println(Thread.currentThread().getName()+"=>"+number);
            // 通知其他线程，我+1完毕了
            condition.signalAll();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
    //-1
    public synchronized void decrement() throws InterruptedException {
        lock.lock();
        try {
            while (number==0){ // 1
                // 等待
                condition.await();
            }
            number--;
            System.out.println(Thread.currentThread().getName()+"=>"+number);
            // 通知其他线程，我-1完毕了
            condition.signalAll();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
}
